Rat Worx MRX Chain Drive Auto Knife

[Quiet Riot]

Though Rat Worx might be new to the knife market, they've been designing and manufacturing gun parts and accessories, aerospace bearings, custom surgical tools, and even robotic hands for a long time. In fact, they spent three years testing the MRX before finalizing on a design for production, and it shows.

Many look at the unique chain drive as a gimmick or potential reliability problem, but I show how the design works and why it makes perfect sense for a knife designed to be the world's strongest auto knife.

[Straight Shooter]

Brother...you always give a great, informative review on things. I really enjoy your vids..and that's an interesting blade!

[ICANHITHIMMAN]

Nice video, looks like a solid unit. Any idea of the cost, their site will not open for me.

[luvmy40]

Their web site shows $325.00 on the MRX

[WillBrink]

Though Rat Worx might be new to the knife market, they've been designing and manufacturing gun parts and accessories, aerospace bearings, custom surgical tools, and even robotic hands for a long time. In fact, they spent three years testing the MRX before finalizing on a design for production, and it shows.

Many look at the unique chain drive as a gimmick or potential reliability problem, but I show how the design works and why it makes perfect sense for a knife designed to be the world's strongest auto knife.

Interesting. I'd be interested in what tests conducted showed it to be "the worlds strongest auto knife." It does look like a very robust knife to be sure, but I always cringe when such a claim gets made. Note at 2:40 or so, the air chisel position to the blade, not the handle, which would be a genuine test of the entire knife, especially the locking mechanism. Any decent blade could do that with chisel placed as it is on the blade. I want to see knives, especially folders, tested at their weakest points, not their strongest as knife companies and testers tend to do.

I'd wager, a twig, pebble, etc, gets stuck in that chain, and game over. Have you actively tried to jam that chain to see how resistant it is to that obvious potential issue? But, congrats to them on thinking outside the box on that design and I look forward to hearing from owners/users and it seems like a solid knife for the $$$.

[Quiet Riot]

Interesting. I'd be interested in what tests conducted showed it to be "the worlds strongest auto knife." It does look like a very robust knife to be sure, but I always cringe when such a claim gets made.

Al set out to make the toughest auto knife available. He didn't make the knife first, then decide to call it that, nor did he think about using a chain drive until he researched the weaknesses of other existing designs. The price reflects his no-holds-barred approach to building this knife, and it wasn't until he and independent evaluators felt he succeeded in building the toughest auto knife that he went ahead with production.

I'd wager, a twig, pebble, etc, gets stuck in that chain, and game over. Have you actively tried to jam that chain to see how resistant it is to that obvious potential issue? But, congrats to them on thinking outside the box on that design and I look forward to hearing from owners/users and it seems like a solid knife for the $$$.

There just isn't any way. First of all, understand that the scenario you're talking about is in *closing* the knife. When closed, every gap in the chain is occupied by a sprocket tooth, and there isn't any way you're going to jam a roller chain in this position because there isn't anything for something to jam on. The rollers will just roll out of the way, and the knife will open. Every time.

Even if you somehow managed to get something between the chain and the teeth while the knife is open, the chain would just conform to the obstruction, and the spring would give extra slack. The chain would then just ride higher on the remaining teeth of the sprocket. There is enough clearance in the slab channel for a huge amount of accommodation in this regard, and I'm actually sitting here testing it out by jamming all sorts of metal objects in there. I will include exactly what I'm talking about in my video on the mini-MRX, which might be a few months.

Rat Worx did plenty of testing with all kinds of mud and lint to show what they already knew about how resistant roller chains are to getting jammed. They subsequently made a few of their own videos in an effort to answer this because yes, it is the #1 concern people raise about the chain.

They also built a custom cycle test machine and show the testing they've don with this device in several different videos.

You can find them all on RAT Worx' very informal YouTube channel here:
http://www.youtube.com/user/junknut1/videos

[WillBrink]

Al set out to make the toughest auto knife available. He didn't make the knife first, then decide to call it that, nor did he think about using a chain drive until he researched the weaknesses of other existing designs. The price reflects his no-holds-barred approach to building this knife, and it wasn't until he and independent evaluators felt he succeeded in building the toughest auto knife that he went ahead with production.

I have no issue with the cost and made no comment on that. I think it's a reasonable price for a well made auto like that as indicated below. But, my point is setting out to make the toughest auto knife available (and it very well may be the case) and claims of actual tests conducted against other similar "proving" it is thus, are two totally different things. Lots of knife makers make such claims as you know. As a researcher type, I get hung up on specific choices of words like that. Wouldn't prevent me from purchase of that knife no, but any time I hear of tests conducted "proving" X to the "best" or "toughest" of it's kind, I wanna see the tests...

There just isn't any way. First of all, understand that the scenario you're talking about is in *closing* the knife. When closed, every gap in the chain is occupied by a sprocket tooth, and there isn't any way you're going to jam a roller chain in this position because there isn't anything for something to jam on. The rollers will just roll out of the way, and the knife will open. Every time.

That makes sense. You don't see the sprocket well in the vid to get an idea of how it fills any gaps a rock, etc could get into. Thanx.

Even if you somehow managed to get something between the chain and the teeth while the knife is open, the chain would just conform to the obstruction, and the spring would give extra slack. The chain would then just ride higher on the remaining teeth of the sprocket. There is enough clearance in the slab channel for a huge amount of accommodation in this regard, and I'm actually sitting here testing it out by jamming all sorts of metal objects in there. I will include exactly what I'm talking about in my video on the mini-MRX, which might be a few months.

Rat Worx did plenty of testing with all kinds of mud and lint to show what they already knew about how resistant roller chains are to getting jammed. They subsequently made a few of their own videos in an effort to answer this because yes, it is the #1 concern people raise about the chain.

They also built a custom cycle test machine and show the testing they've don with this device in several different videos.

You can find them all on RAT Worx' very informal YouTube channel here:
http://www.youtube.com/user/junknut1/videos

Excellent info, and what I was looking for. Thanx.

[ra2bach]

I think the mechanism is a great departure from the normal/standard. I liked your reference to dirt bike chains when when talks about it's reliability (haha). but for a knife billed as the world's strongest auto knife there sure is a lot of metal removed from the spine. to me, it looks like the majority of steel is on the sharpened (thinned) portion of the blade. I'd be happier if they just put a thumb stud there or if needed for the locking mechanism, just one hole...

[WillBrink]

I think the mechanism is a great departure from the normal/standard. I liked your reference to dirt bike chains when when talks about it's reliability (haha). but for a knife billed as the world's strongest auto knife there sure is a lot of metal removed from the spine. to me, it looks like the majority of steel is on the sharpened (thinned) portion of the blade. I'd be happier if they just put a thumb stud there or if needed for the locking mechanism, just one hole...

In my experience, comparative testing tends to end hype. Don't bill it as such, show it as such, and do so compared to like products.

[ra2bach]

In my experience, comparative testing tends to end hype. Don't bill it as such, show it as such, and do so compared to like products.

true. my comment was on the slots in the spine portion of the blade. they don't leave a lot of metal in that area and looks to me like it weakens it...